map_indices(, ::MOI.NLPBlockData) is wrong

[mlubin]

The issue in jump-dev/JuMP.jl#2037 is that the variable indices are permuted 2 <-> 1 between JuMP and Ipopt.jl. The starting points therefore get swapped. The NLPBlock is unaware of the permutation of indices. Wrapping the NLPBlock to permute all the indices in the evaluation callbacks would be wasteful work. IMO we should instead guarantee that default_copy_to maintains the original ordering of the variables.

This is a blocker for JuMP 0.20.